最简单下拉框二级联动

<script type="text/javascript">

function loadCity(province) {

$.ajax({

type: "POST",

url: "aa_getCity.do?dateparam=" + new Date(),

data: {"province":province},

dataType:"json",

async : false,

success: function(json){

$("#city").empty();

$("#city").append("<option value=''></option>");

for(var i = 0; i < json.length; i++){

if(json[i] != null) {

$("#city").append("<option value="+json[i]["cityid"]+">"+json[i]["cityname"]+"</option>");

}

}

},

error:function (XMLHttpRequest, textStatus, errorThrown) {

alert("加载城市异常：" + errorThrown);

}

});

}

</script>

<td class="class1" width="20%">省份:</td>

<td class="class2" width="30%">

<select name="province" id="province" onchange="loadCity(this.value);">

<option value=""></option>

<option value="00">北京</option>

<option value="01">广东</option>

</select>

</td>

<td class="class1" width="20%">城市:</td>

<td class="class2" width="30%">

<select name="city" id="city" ></select>

/td>

java:

public void doGetCity()

{

try {

String province = getRequest().getParameter("province");

List<Map<String,String>> resultCityList = new ArrayList<Map<String,String>>();

List cityList = new CityList();//根据省份从数据库或者其他地方取值

for(CityListObj obj : cityList){

Map<String,String> tmpMap = new HashMap<String,String>();

tmpMap.put("DICTID", obj.getCityId());

tmpMap.put("DICTNAME", obj.getCityName());

resultCityList.add(tmpMap);

}

}

JSONArray jsonArray = JSONArray.fromObject(resultCityList);

PrintWriter out = getResponse().getWriter();

out.print(jsonArray.toString());

out.close();

}

catch (Exception e) {

logger.error(e.getMessage(),e);

}

}